Pinhole : A short unwelded area in the weld line extending through the entire pipe thickness so that fluid will leak out through the area very slowly. (Bul 5T1)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}